Precision wheel truing mechanism



Aug. 28, 1951 w. A. HOIER PRECISION WHEEL TRUING MECHANISM 2 Sheets-Sheet 1 Filed June 20, 1947 INVENTOR. WAL TERA-H0158 BY mug ATTORNEYS g- 28, 1951 w. A. HOIER 2,565,687

PRECISION WHEEL TRUING MECHANISM Filed June 20, 1947 2 Sheets-Sheet 2 INVENTOR.

I W227? A. H0153 A TTOJP/VZYS Patented Aug. 28, 1951 UNITED STATES PATENT OFFICE PRECISION WHEEL TRUING MECHANISM Walter A. Hoier, Cincinnati, Ohio, assignor to The Cincinnati Milling Machine 00., Cincinnati, Ohio, a corporation of Ohio Application June 20, 1947, Serial No. 756,006

Claims. 1

This invention relates to improvements in wheel truing mechanism and has particular reference to an improved form of truing device adapted for use in proper formation of the surface of the grinding wheel of a precision grinding machine.

One of the principal objects of the present invention is the provision of a unitary mechanism capable of embodiment in and as a part of a grinding machine or applicable as a precision attachment to existing machines.

Another object of the present invention is the provision of a free floating mounting for a wheel truing mechanism which will facilitate the arouate following of the shape pattern during high speed precision truing operations.

A further object of the invention is the provision of a sensitively operating truing mechanism particularly adapted for the performance of contour or profile truing operations.

A further object of the invention is the provision of improved control mechanism for effecting the necessary operations and adjustments of the truing device mechanism.

Other objects and advantages of the present invention should be readily apparent by reference to the following specification, considered in conjunction with the accompanying drawings forming a part thereof, and it is to be understood that any modifications may be made in the exact structural details there shown and described, within the scope of the appended claims, without departing from or exceeding the spirit of the invention.

Figure 1 represents a vertical sectional view of the truing mechanism as applied to the wheel housing of a grinding machine.

Figure 2 is a horizontal sectional view on the line 2-2 of Figure 1.

Figure 3 is a vertical sectional view at right angles to Figure 1 taken as on the line 3-3 of that figure.

Figure 4 is a fragmentary view partly in section and partly in plan as on the line 4-4 of Figure 1.

Figure 5 is a sectional view of an alternative form of cam clamp.

Figure 6 is a view in elevation of the profile cam and follower, the supporting parts being shown in section as on line 6-6 of Figure 1.

Figure 7 is a diagrammatic view of the hydraulic traversing means for the truing device.

In the drawings in which similar reference characters are employed to denote similar parts, the numeral l0 designates the wheel guard housing of a grinding machine which may, for ex- .ample; be of the type shownin U. S; Letters Patcut 2,367,759, it being understood that this housing is rigidly mounted on the bed of the grinding machine. Suitably mounted on the portion l l of the housing is the base unit [2 of the present invention which is provided with the dovetail ways I3 for thevtransversely or horizontally movable slide unit l4. As shown in'Figures 1 and 2,.the member l2 has formed therein the cylinder chamber l5 receiving piston I6 whose rod l1 extends through the stufiing box members 18 forming a closure for the outer end of the cylinder. Terminally secured to this piston rod I1 is a drive plate l9 coupling the rod with slide 14 for transverse actuation thereof.

As indicated in Figure 7, there is provided a hydraulic medium reservoir 20 from which actuating fluid is discharged by pump 2| into pressure conduit 22 extending to the valve block 24 containing a valve actuable by the handle 25 which in the intermediate position shown couples the pressure from line 22 with reservoir conduit 26. In its other positions of adjustment this valve connects the pressure conduit with either cylinder conduit 2'! or cylinder conduit 28 and alternatively the other of these conduits with the reservoir, con- ;duit, or exhaust line 26 so that the piston will be suitably actuated in one direction or the other for translation of the slide in accordance with the movement of control handle 25.

The slide is provided with a pair of flanges 29 and 30 forming a guide channel extending vertically or at right angles to the direction of movement of the slide as determined by the ways I3. Secured to ,the slide adjacent flange 29 is a guide rail 3| formed with a track or groove at 32 engageable with a series of anti-friction bearing members 33 maintained in spaced relarger in diameter than the retaining bolts or studs 43, rendering same capable of transverse adjusting movement. This can best be effected byadjusting screws 44 carried-by the flange-.29 and abutting the. guide bar. 3l near-its "ends to effect exact desired positioning of same. :When this has been efiected the adjusting screws themeither event the earn is selves are preferably looked as by nuts and the rail then firmly secured by tightening of thebolts 43.

With the parts in this position it will be noted that the unit or housing 39 is supported for extremely free vertical floating movement by the multiplicity of anti-friction bearing members 33 and 3'! which, due to the relative adjustment of the outer guide bars firmly support the housing against any torsional or angular deflections. To retain the anti-friction members in proper position between the bars use is preferably made of the limiting pins 46 carried by the housing and engageable with the ball cages -3'4and 38.

As particularly indicated Figure 2 the housing 39 is formed with the central cylindrical bore 41 to receive the truing tool holder 48 which is preferably cylindrical in form and provided at one side with a keyway 49 to receive the sliding key 50 mounted in slot 51 of the housing. Springs 52 serve to press the key inward into frictional interlocking engagement with the tool holder while a clamp screw 53 carried by removable block 54 on the side of the housing maybe employed to force the key into tight clamping en- 'gagement with the tool holder. When this screw is loosened the tool holder may be longitudinally adjusted in the housing as by adjusting screw 55 swiveled in cap 56 at the top of the housing and provided with operating member or handle 51. In this manner very fine incremental adj ustments may be made "on the tool holder longitudinally with respect to the housing, and it may be suitably locked in adjusted position to eliminate any possible accidental shifting due to tooling vibration or otherwise.

While the truing mechanism here illustrated can be employed for producing rounded, straight, or other peripheral transverse configurations as desired on the grinding wheel 58, it is to be understood that it is particularly adapted for use in the production of contoured surfaces for performance of form grinding operations. To control the shape or configuration produced on the surface of the wheel there is-removablysecured tothe rear of the slidable housing '39 a block 60 having a follower 6| in the form of a knifeedge point adapted to ride over the surface of the contoured cam 62 for controlling the movement of the diamond or truing tool 63,"!813iblV6 to the surface of the wheel.

This guide cam 62-:has its lower face resting -'on the face [53' of mounting block 64 secured on suitable seat formed on the upper portion of the base l2. This block is further provided with the angular-1y related seating face 65 for engage ment with the rear of the 'cam guide. 'Figures 1 and 4 the cam is indicatedas held againt face '65 by bolts 66 and as having reduced end portions 61 engaged by lugs-l38 on clampplate 69. This plate has a slot H! to receiv e bolt 1-! carried by the block 64. 'Loosenin'g of the bolt permits 0f retraction of the plate to disengage the cam while when sli'd-i-ntoforward position and tightened the lugs hold the cam down against i "the -facefifi3". "-tion .has been illustrated in Figure :5 in which An alternative formbf construethe cam itself is formed with a -doveta'il portion 12 .intcrfitting with a taper portion T3 onjthe clamp plate '69 :so that tightening of bolt 11 serves to both hold the cam-downwardly against the face 63 and also draw the 0am rearwardly against the angularly related seating face 65. In

base portion 'IJI.

supported by the To facilitate raising of the truing tool and housing as a unit to move the diamond point 63 out of truing position and at the same time retract the follower 6! with respect to the cam 62, there is journaled in the lower portion of the front closure plate 14, mounted on the face of the slide 14, a cylinder 15 rotatable by handle '16. This cylinder has a notched or cutaway portion as at 1-! providing the cam or lifting finger 18 adapted when the lever is in its forward or counterclockwise position as shown in Figure l to inter engage with the lug '19 at the lower portion of the housing 39. Continued counterclockwise movement of the handle 16 as viewed inFigure 1' will oscillate cylinder 15 and thus raise the housing until the shoulder at contacts with cap plate 59, Alternatively, when handle 16 is shifted in a clockwise direction past its dead center position, the cam finger 18 will be moved entirely out of the path of movement of lug 19 on the housing, leaving the housing free floating and neither restrained against downward movement nor having its downward movement accentuated by the weight of the handle and associated parts as would be the result if conventional rack and pinion or like mechanisms were employed for effecting this shifting movement.

It will be understood that during the performance of the truing operation, th xgrinding wheel is rotated at a suitable truing speed and due to this rotation tends to exert a displacing side thrust against the truing 'tool and its supporting mechanism as illustrated in Figure 1.

While it is preferable that the 0001 be absolutely free floating and without frictional restraint, to prevent :any undue displacement thereof, the plate 8| is secured to the wheel housing l0 and carries the guiding 82 and 83 laterally spanning the lower rectangular portion of the shiftable truing tool housing, limiting any possible deflection thereof. To retain coolant and grit displaced durin truing within the housing for proper exhaust from the operative portion of the machine, there is mounted on the guides 82 and 83 sliding cover 34 of an extent to close over the space between the guides in any position of movement of the housing, the housing 39 loosely sliding through a suitable-aperture as at '85 in this cover plate.

Coolant is supplied to the g-riding wheel for grinding, truing and other operations in the con-- ventional manner as by the spray pipe 86 extending inward through the housin Ill and connected by suitable piping connections 8'! with the coolant source-notshow-n. 7

It is to be understood that incontour or other grinding wheel truing operations it is desirable that the tool, such :as the diamond point 88, traverse the wheel at a relatively rapid rate for removal of a very fine increment from the surface of the wheel to restore its cutting efficiency and maintain the desired curvature withoutpro- 'duction of peripheral groovings or the like tending to mar the work. It is, therefore, ordinarily necessary that the "tool be held against the work with but a very light pressurabu't it is absolutely essential in the case of form grinding that the movements of the truing tool exactly correspond with thefor-m of its guide or patter-n and that there be no lag or delay in its in and out movements, resulting in a different contour on the wheel surface from that of the guiding pattern. Difficulty has hitherto been experienced in this connection with ordinary types of truing 'dearranges? vices even when appreciable pressure is applied thereto in the direction of the grinding wheel.

' The present invention obviates these difliculties in that the tool support and housing are mounted for extremely free floating movement, eliminating retarding friction tending to cause such lag and permitting the follower continuously to conform to the exact outline of the pattern, a matter of extreme importance as the resultant product of the grindin machine is frequently required to be to precision limits within .0001" to .0002". Production of a surface on the grinding tool of accuracy to attain such product is effectable by the use of the free floating mechanism here illustrated.

It will further be understood that under ordinary conditions the weight of the free floating parts is suflicient to hold the point 88 against the periphery of the grinding wheel 58 with adequate pressure for truing purposes but, if desired, a pressure or vibration dampening spring, such as indicated at 89 may be inserted between the end plate 59 and shoulder 80 on the truing tool housing. Additionally, the handle element 16 is manually engageable by the operator for determinin or aiding and controlling the reactions of the tool.

As indicated in Figure 6, the contour pattern itself is provided with the extended shoulders 90 on which the follower 6| may rest in a displaced position at one side or the other of the grinding wheel 58 intermediate the truing operations. For performance of truing it is then merely necessary to actuate a handle 25 to effect the desired number of strokes of the truing tool across the face of the wheel.

What is claimed is:

1. A truing device for a grinding wheel or the like including a base having an external transverse guide, a truing slide mounted on the guide and reciprocable relative to the base, ways carried by the slide and extending transversely with respect to the guides for the slide, a truing unit mounted between said ways, a plurality of anti-friction bearing elements intervening the ways and the truing unit whereby the latter is supported for free floating movement with respect to the slide, said truing unit comprising an outer housing member, a contained truing tool holder, an actuator for the holder carried by the housing member havin a portion engaging the holder for effecting relative adjustment of said holder and member, the tool holder being mounted for sliding movement in the housing and having a keyway formed at one side thereof, an aligning wedge key supported by the housing for movement toward and from the keyway in the tool holder, and a spring interposed between the housing member and the key for resiliently urging the key into the keyway.

2. A truing device for a grindin wheel or the like including a base having an external transverse guide, a truing slide mounted on the guide and reciprocable relative to the base, ways carried by the slide and extending transversely with respect to the guides for the slide, a truing unit mounted between said ways, a plurality of antifriction bearing elements intervening the ways and the truing unit whereby the latter is supported for free floating movement with respect to the slide, said truing unit comprisin an outer housing member, a contained truing tool holder, an actuator for the holder carried by the housing member having a portion engaging the holder for efiecting relative adjustment of said holderand member,- the tool holder being mounted for sliding movement in the housing and having a keyway formed at one side thereof, an aligning wedge key supported by the housing for movement toward and from the keyway in the tool holder, a spring interposed between the hous-i ingand the key for resiliently urging the key into the keyway, and a clamp carried by the housing for forcing the key into tight engagement with the tool holder to lock the same in position within the housing.

3. The combination with. a grinding machine having a wheel housing of a truing mechanism including a base carried by the wheel housing having a-transversely extending guide portion, a slide mounted for translation on said guide portion, said slide having a pair of spaced flanges providing a housing receiving space therebetween, a guide rail carried by one of said flanges having an elongate ball receiving groove formed therein, a second guide rail having a ball receiving groove secured to the other flange in opposed relation to the first rail, means carried by the slide for adjusting said second rail in a direction toward the first for varying the separation therebetween, a truing unit housing disposed intermediate said rails having longitudinally extending ball receiving grooves, and anti-friction bearings for floatingly mounting the housing with respect to the flanges of the slides including elongate cage plates individual to the respective opposed grooves of the housing and flange members, anti-friction balls jointly mounted in said opposed grooves and held in spaced relation by the elongated cage members, means on the housin for limiting the relative movement of the cage members with respect to the housing, whereby the balls will be retained in operative relation to the respective grooves during relative adjustment of the parts and will support the housing for free floating vertical movement while preventing tilting or twisting thereof with respect to the supporting slide, the truing unit housing having a terminal guide portion, and spaced guides carried by the wheel housin for cooperation with the guide portion of the truing unit housing, said guides extending parallel to the transversely extending guide portions of the base in spanning relation to the terminal guide portion of the truing unit housing and interfitting therewith to prevent deflection of the terminal portion thereof during truing op-- erations.

4. A truing mechanism of th character described including a base having a transversely extending guide portion, a slide mounted for translation on said guide portion, said slide having a pair of spaced flanges providing a housing recieving space therebetween, a guide rail carried by one of said flanges having an elongate ball receiving groove formed therein, a second guide rail having a ball receiving groove secured to the other flange in opposed relation to the first rail, means carried by the slide for adjusting said secand rail in a direction toward the first for varying the separation therebetween, a truing unit housing disposed intermediate said rails having longitudinally extending ball receiving grooves, and anti-friction bearings for floatingly mounting the housing with respect to the flanges of the slides including elongate cage plates individual to the respective opposed grooves of the housing and flange members, anti-friction balls jointly mounted in said opposed grooves and held in spaced relation by the elongated cage members, means on the housing for limitin the relative movement cf the cage members with resp ct to thehousing, whereby the balls will be, retained inoperative relation'to the respective grooves during relative adjustment of the parts and will support the housing for free floating vertical movement while preventing tilting or twisting thereof with respect to the supporting slide, and means for controlling the position of the housing including an abutment formed on the housing an actuator pivoted to the slide havin a finger movable into position to engage and shift the abutment and a relieved portion movable into registry with the path of movement. of the housing to permit unobstructed movement thereof.

5. A truing mechanism of the character describedincluding a base having a transversely extending guide portion, a slide mounted .for translation on said guide portion, said slide having a pair of spaced flanges providing a housing receiving space therebetween, a guide rail carried by one of said flanges having an elongate ball receiving groove formed therein, a second guide rail having a ball receiving groove secured to the other flange in Opposed relation to the first rail, means carried by the slide for adjusting said second rail in a direction toward the first for varying the separation therebetween, a truing unit housing disposed intermediate said rails having longitudinally extending ball receiving grooves, and anti-friction bearings for floatingly mountingthe housing with respect to the flanges of the slides including elongate cage plates individual to the respective opposed grooves of the housing and flange members, anti-friction balls jointly mounted in said opposed grooves. and held in spaced relation by the elongated cage members, means on the housing for limiting the relative movement of the cage members with respect to the housing, whereby the balls will be retained in operative relation to the respective grooves during relative adjustment of the parts and will support the housing for free floating vertical movement while preventing tilting or twisting thereoi with respect to the su porting slide, and means for controlling the position of the housing including an abutment formed on the housing and an actuator pivoted to the slide having a finger movable into position to engage and shift the abutment, said actuator having a portion cut away adjacent the finger to provide a recess in proximity to the abutment, and an actuating handle carried by the actuator and positionable to one side of dead center for effecting interen- 'gagement of; the finger and abutment to shift v REFERENCES CITED The following references are of record in the file of this patent:

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